IMAGE COMPRESSION BASE ON DCT DWT

IMAGE COMPRESSION BASE ON DCT DWT 2012/12/07 Ying Wun, Huang

OUTLINE • Why DCT DWT? • Proposed Method • Proposed Method-Residue • Appendix: C Code Interview Questions

Why DCT DWT? • The scan order of loading image

Why DCT DWT?

Proposed Method • 8×256 DCT DWT Compression

Proposed Method • DCT+DWT

Proposed Method • JPEG×JPEG2000 Quantization First row of JPEG2000 × ÷12 First column of JPEG

Proposed Method • JPEG×JPEG2000 Quantization

Proposed Method

Proposed Method-Residue • Residue With DCT DWT Compression

Proposed Method-Residue - = Resize: 512×512 512×512 OriginalImage Residue

Proposed Method-Residue • MPEG4-inter×JPEG2000 Quantization First row of JPEG2000 × ÷16 First column of MPEG4-inter

Proposed Method-Residue • Simulation Result

Appendix: C Code Interview Questions • Coding Style if(x==2) if(2==x)

Appendix: C Code Interview Questions • Coding Style Compile if(x=2) DONE Compile if(2=x) ERROR

Appendix: C Code Interview Questions • Example x=2 intx=1,y=5; if(x=2) y=3; return; Compile x=?, y=? y=3 x=0 int x=0,y=5; if(x=0) y=8; return; Compile x=?, y=? y=5

Appendix: C Code Interview Questions • Property of XOR Z = X^Y X = X^Z Y = Y^X X = 7 Y = 3 X = 3 Y = 7

Appendix: C Code Interview Questions • Exchange two variables without TEMP TEMP=x; x=y; y=TEMP; x=x^y; y=y^x; x=x^y; x^=y^=x^=y;

Appendix: C Code Interview Questions • Do Not Use “if else,…” if x is true, than r=y. r=x?y:z; if x is false, than r=z.

Appendix: C Code Interview Questions char func(char x, char y, char z) { return } • x*y|!x*z;

The End.

IMAGE COMPRESSION BASE ON DCT DWT